«;{ 



r- 

 ion 



to be ascribed in part to tlie formation of carhon dioxide. Acco 

 ding to the researches of Bornkmann (1920) the CO.^ concenlral 

 över manured ground may rise considerably above Ihé normal. 



By the sea-shore the seaweed cast up acls as natural manure. 

 Especially when the beds of seaweed on iow-lying and protecled 

 shores decompose inlo mud are enormous quanlilies of CO,, deve- 

 loped. The figures given on p. fiS show thal the CO, prochicUon of 



Plioto, the atitlior. 

 Fi^ 9. The vegetation on the fucoid mud on the shore. The plants are Nasturiiuni 

 palustre, Rmnex mantimus, Rnnmiculus scelerafus and Bidetis iripartita. 



the decomposed seaweed considerably exceeds that of the best foresl- 

 mould. The luxuriant vegetation on the damp beds of seaweed 

 and mud is doubtless partly due to this fact. The wind naturally 

 prevents the occurrence of very great CO2 tension in the air, bul 

 since proslrate forms predominale in the shore-vegetation, and espe- 

 cially in the seaweed, a part of the upward-ditTusing carbon dioxide 

 must naturally succeed in being absorbed Ihrough the stomala of the 

 under sides of the leaves. These prostrate shore-planls are Ihereforc 



